Muffler or silencer



2 Sheets-Sheet 1 X WT E I MI INVENTOR flXEZ r9. HILL Ofi/NG'.

' WITNESS A; ATTORNEYS Oct. 13,1925.

A. A. HILLDRING MUFFLER OR SILENCER Filed Feb. '20.

1922 2 Sheets-Sheet Patented Oct. 13, 1925.

UNITED STATES AXEL A. HII JLDRING, OF SAN FRANCISCO, CALIFORNIA.

MUFFLER on SILENCER.

Application filed February 20, 1922.

To all whom it may concern Be it known that I, AXEL A. HILLnnrNc, a citizen of the United States, and a resident of the city and county of San Francisco, State ofCalifornia, have invented a new and useful Mufller or Silencer, of which the following is a specification.

This invention relates to means for reducing the noise of the exhausting gases from internal combustion and explosive engines, such means commonly being termed silencers.

An object of the present invention is to provide a simple, substantial, durable and practicable device for effectually eliminating the exhaust sounds of engines of the combustion and explosion type,

Another object of the invention is to provide a device of this kind which is compact in arrangement and which, within its shell, provides a circuitous path of travel from end to end of the shell and through which path of travel, the gases under pressure are caused to have not only changes of direction at right angles to each other, but also which have a spiral direction of flow. In this connection; an object is to provide a mufiler having a series of chambers successively increasing in length from the intake to the discharging end of the muffler and having also a series of chambers successively increasing in diameter from the intake to the discharge end of the chamber. Further, an object is to provide a mufHer with an inner series of chambers increasing in diameter and a concentric series of cham bers surrounding the inner chambers and which successively increase in length, all with the object of effectively reducing the exhaust sound without restricting or retarding the escaping gases.

The invention possesses other objects and features of advantage, some of which, with the foregoing, will be made manifest in the following description of the preferred form of the invention, which is illustrated in the drawings accompanying and formingpart of the specification. 'It is to be understood that it is not intended to limit the invention to the embodiments shown by the said drawings and description, as variations may be adopted within the scope of the invention as set forth in the claims. 1

Figure 1 is a perspective and longitudinal,

sectional view.

, A modified form of the invention is show! Serial No. 537,699.

in central, longitudinal section in Figure 2.

The mufiier of my invention consists broadly of a cylindrical exterior shell having at opposite ends intake and discharge heads and between these and within the shell there is arranged substantially two series of separate chambers, means being provided in certain of the chambers for deflecting the gases so as to impart to them a spiral or rotary movement.

More particularly the .mufiier has an exterior cylindrical shell S closed at one end by the intake head I, which has a nipple N to be connected to the exhaust pipe or outlet means of an engine. At the opposite end of the shell is the outlet head 0, having a discharge pipe P.

. In the illustrated embodiment the muffler is provided with six expansion and separate chambers designated in their order in the circuit, as 1, 2, 8, 4c, 5 and 6, which are spaced longitudinally and formed by transverse partitions 7, 8 and 9, and by the inner cylinders 11, 12 and 13.

The chamber which is formed between the intake head I and the partition 7, receives 4 the hot gases entering through the nipple N and then passing, as shown by the arrows, outwardly toward the perimeter of the partition which is provided with a series of tongues 14: formed by radially slitting the margin of the partition 7. The tongues 14 are each symmetrically bent upwardly from one side of the partition 7 and are also bent y a twisting action disposing the ends of the blades at an angle with the plane of the partition 7, as is clearly shown in the drawing. The pitch or inclination of the blades 14 obviously may be varied and determined according to the given conditions to which the muffler will be subjected. This formation of blades at the perimeter of the partition 7 produces a series of apertures between the contiguous radial edges of each blade and the gases flow through these apertures and are impelled in a common circular direction, as shown by the arrows b in the chamber 2. As the partition or disc 7 forms one end of the second chamber 2, its opposite end is formed by the disc or partition 8 and this is shown as having a central aperture 8 which is surrounded by the short section of cylinder 11.

This cylinder is apertured asby punching inwardly a multiplicity of tongues 11, which are inclined downwardly toward the able size and arrangement, these being in- A clined downwardly toward the partition 8 on which the lower end of the drum 12 is arranged. Therefore the moving gases are again reversed in their direction as they pass through the cylinder 12 and are deflect ed downwardly toward the plate 8, which, in turn, deflects them upwardly, as shown by the arrows (Z in chamber 4, which is the second outer chamber and is, as shown, of considerably greater len h than the chamher 2. From the cham er 4, the moving gases pass through apertures provided by upwardly struck and circumferentially twisted tongues 9 in the margin of the partition 9, which forms the top of the chambers 12 and 14. The twisted tongues or blades 9 serve to deflect the moving gases, as shown by the arrow e, in chamber 5, which, in turn, is longer than the chamber 4 and is closed at one end by the outlet head 0. The gases in the chamber 5 flow inwardly through apertures 13", provided in the cylinder 13 which is arranged between partition 9 and the outlet head and this cylinder is also of lar r diameter than the cylinder 12. It is obvious that the cylinder 13 may be provided with deflecting tongues, such as 11 The movement of the gases after passage throu h the cylinder .13 is then again de flecte by the inwardly extending end of the discharge pipe P.

It will, therefore, be observed that the high pressure gases entering the first chamber pass with a deflected movement into the second chamber 2, wherein they are iven a circulating movement and then pass into the elongated inner chamber 3. The travel of the gases entering the chamber 3 is deflected bythe inclined deflectors 11 in the cylinder 11 'and is further swerved by the outwardl inclined tongues 12 in the cylinder 12. The deflectin efiect is again secured by the passage of tEe gases through the a ertures between the deflecting tongues 9 0 the partition 9 and the circulating movement of the gases in the chamber 5 also serves to silence the ultimate discharge.

It is manifest that the structural elements of the improved mufiier may be varied as the conditions may demand and the elements may be secured together for convenient assembly and detachment. In the resent case the cyhndrical shell S is ided on. its

surface with a series of an le brackets 15 upon which may be secured e intermediate partitions 7, 8 and 9 and also these may be further secured and braced by spacin sleeves 16 mounted upon respective longitudinal stay bolts or rods 17 assing through 'the inlet head I and the out at head 0 and through the several partitions.

An embodiment of the invention in a different form is illustrated in Fig. 2 in which the shell consists of a plurality of sections S, S, S and S respectively lncreasing in length from one end of the silencer or muffler to the other but being of substantially the same diameter. In this form of the silencer the end section 'S is provided with an integral and wall I. as distin ished from the separate head I of Fig. 1. e op osite end of the silencer is closed b a suitable head 0 bolted to the longest she 1 section S. A feature of this form of silencer is that one or the other of the meeting ends of sections S S, S and S is rebated or countersunk, as at 20, sufliciently to form a seat for respective intermediate partitions 7, 8 and 9 extending transversely across the silencer or mufller and therefore being clamped between the meeting edges of the sections when these are bolted together, as by bolts 21. This'forms an extremely simple form of assembly for the parts of the silencer.

The marginal portion of the transverse partition 7 is provided with radial apertures 14 whose parallel walls are inclined all in a common direction, as shown by the arrows 1;, so that as the gases ow from chamber 1 into the next and outer chamber 2, a spiral motion is imparted to the same.

In this form of the silencer the innermost chambers 3 and 6 are shown as of equal diameter and are formed by sections of cylinders .11" and 12", these forming the chamber 3, and cylinder 13 which forms, above the transverse partition 9, the chamber 6 and from which leads an exhaust pipe P shown as'perforated. The bottom of the chamber. 3 of the form of silencer in Fig. 2 is in the form of an inverted cone 22 serving as a deflector for throwing the gases from the inlet N outwardly. The chamber silencer 11 is provided with inwardly inclined nozzles 11 forming inlet apertures through which the flow inwardly from chamber 2 to chamber 3 and thence into the upper cylinder section 12 which is provided with outwardly inclined nozzles 12 forming apertures in the cylinder. The gas flowing through these apertures i1111 themsrhell Election S and froflm thill; 01175111 cam n: owtro radial apertures 9" having inclined late ral walls, so as to impart the circular movement as shown by the dotted arrows 9, as the gases enter the lower portion of the upper and outer chamber 5 above the partition 9.

The inner cylinder 13 is provided with outwardly inclined nozzles 13 forming apertures through which the gases flow inwardly into the inner and exhaust chamber 6 which is within the cylinder 13". The gases then flow into the discharge pipe P through its lower open end an also through its rforated wall. A simple and economical orm of construction shows the partitions 7, 8 and 9, and the inner face of the head 0 all having countersunk or rebated seats to receive the contiguous ends of the respective inner cylinders 11", 12 and 13". The transverse partition 8 has a central opening for permitting the formation of a common chamber 3 within the cylinders 11 and 12", but the partition 9 is closed between the adjacent ends of the cylinder 12" and the cylinder 13 to pre-. vent the flow of gas directly from chamber 3 to chamber 6 and therefore causing it to flow outwardly and through the radial and inclined deflecting passageways 9. It will be seen, therefore, that each of the shell sections forms with. theintermediate partitions outer chambers of. increasing length from end to end of the silencer or muflier.

It will be seen that the mufller is constructed of very simple and inexpensive parts all of which may be readily assembled and securely fastened and that renewals and changes may be made expeditiously when necessary.

What is claimed is:

1. An exhaust mufller having): series of inner axially arran cham rs and a series of outer cham rs providing for a zig-zag flow between the mner and outer and means in certain of the for producing a circular flow of the gases 2. An exhaust mufller hav' inner axially arran series of outer cham chambers, chambers a series of providing for a zig-zag flow between the inner and outerchambers, and means in certain of the chambers for produ a circular flow of the gases; certain of e chambers having means for reversing the flow of 3. An exhaust mufler having a series of cham rs and a.

of gases.

4. An exhaust muflier comprising a shell having an inlet head, an outlet head, a set of partitions dividing the shell into sepa: rate outer chambers, and means forming separate inner chambers to form a continuous zig-zag path from end to end of the shell; certain of the partitions having marginal means for imparting a circular flow to the moving gases. 0

5. In an exhaust mufller, a shell, a partition disc dividing the shell into two chambersand a plurality of struck up tongues on the periphery of the disc contactin with the shell, said tongues being twiste symmetrically to form inclined deflectors for imparting a common direction ment to a flowing fluid.

6. In an exhaust mufiler, a casing, a partition disc dividing the casing mto two chambers and contiguous twisted tongues formed on the periphery of said disc to cause circular movement of fluid passing between said tongues.

7. An exhaust mufller, comprising a shell having an inlet head and an outlet head, transverse partitions dividing the shell into separate outer chambers, the partitions vbe ing disposed so that the chambers are of increasin length in the direction of flow of the ex aust, the alternate partitions beng provided on their peripheries with twisted tongues to impart circular movement to the exhaust gases, an intermediate partition being provided with a central aperture, rforated inner casings disposed between e alternate partitions and registering with said aperture and tongues on the inner casing overlying the perforations therein to reverse the direction of flow of the gases.

In testimony whereof, I have hereunto set my hand.

AXEL A. HILLDRING.

of move- 

